JP2016070772A - Rader system, vehicle control system, and signal processing method - Google Patents

Rader system, vehicle control system, and signal processing method Download PDF

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Publication number
JP2016070772A
JP2016070772A JP2014199811A JP2014199811A JP2016070772A JP 2016070772 A JP2016070772 A JP 2016070772A JP 2014199811 A JP2014199811 A JP 2014199811A JP 2014199811 A JP2014199811 A JP 2014199811A JP 2016070772 A JP2016070772 A JP 2016070772A
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Japan
Prior art keywords
target
data
stationary
target data
road
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JP2014199811A
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Japanese (ja)
Inventor
伸也 青木
Shinya Aoki
伸也 青木
久輝 浅沼
Hisateru Asanuma
久輝 浅沼
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富士通テン株式会社
Fujitsu Ten Ltd
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Priority to JP2014199811A priority Critical patent/JP2016070772A/en
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88Radar or analogous systems specially adapted for specific applications
    • G01S13/93Radar or analogous systems specially adapted for specific applications for anti-collision purposes
    • G01S13/931Radar or analogous systems specially adapted for specific applications for anti-collision purposes between land vehicles; between land vehicles and fixed obstacles
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06Systems determining position data of a target
    • G01S13/08Systems for measuring distance only
    • G01S13/32Systems for measuring distance only using transmission of continuous unmodulated waves, amplitude-, frequency- or phase-modulated waves
    • G01S13/34Systems for measuring distance only using transmission of continuous unmodulated waves, amplitude-, frequency- or phase-modulated waves using transmission of frequency-modulated waves and the received signal, or a signal derived therefrom, being heterodyned with a locally-generated signal related to the contemporaneous transmitted signal to give a beat-frequency signal
    • G01S13/345Systems for measuring distance only using transmission of continuous unmodulated waves, amplitude-, frequency- or phase-modulated waves using transmission of frequency-modulated waves and the received signal, or a signal derived therefrom, being heterodyned with a locally-generated signal related to the contemporaneous transmitted signal to give a beat-frequency signal using triangular modulation
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/03Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
    • G01S7/032Constructional details for solid-state radar subsystems
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01SRADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35Details of non-pulse systems
    • G01S7/352Receivers
    • G01S7/354Extracting wanted echo-signals
    • G01S2013/93271

Abstract

A technique for accurately determining whether a stationary target is an obstacle on the road is provided. A radar apparatus determines whether another stationary target exists at a position in the vicinity of a reference target that is a stationary target that is present at the shortest vertical distance from the position of the vehicle. . The radar device makes it easy to distinguish a reference target as an obstacle on the road when the number of other stationary targets existing near the reference target is equal to or less than a predetermined number. As a result, the radar apparatus can accurately determine the stationary target of the obstacle on the road, and can reliably output the target data to the vehicle control apparatus. [Selection] Figure 2

Description

  The present invention relates to data derivation processing relating to an object.

  Generally, a radar apparatus receives a reflected wave from an object, and derives a moving target or a stationary target based on a peak signal of the reflected wave. The radar apparatus outputs target data of these targets to a data using apparatus that uses the data. The data use device is, for example, a vehicle control device that controls a vehicle. The vehicle control device uses the target data acquired from the radar device to control the behavior of the vehicle, and provides safe and comfortable travel for the user of the vehicle.

  In addition, when the radar apparatus derives a stationary target existing in the traveling direction of the vehicle, the radar apparatus determines whether the stationary target is an obstacle on the road that prevents the traveling of the vehicle. When the stationary target is a road obstacle such as a stationary vehicle, the road obstacle and the vehicle may collide. Therefore, the radar device outputs target data of the stationary target to the vehicle control device when the possibility that the stationary target is an obstacle on the road is high. The vehicle control device that has acquired the target data performs vehicle control such as decelerating the speed of the vehicle and avoids a collision between the vehicle and an obstacle on the road.

  On the other hand, the radar apparatus does not output the target data of the stationary target to the vehicle control apparatus when the possibility that the stationary target is an obstacle on the road is low. Stationary targets other than road obstacles derived by the radar device are, for example, road signs and traffic lights provided above the roadway, road obstacles such as guardrails provided on the side of the roadway, etc. . A stationary target such as an upper object has no danger of colliding with the vehicle. Therefore, when there is a high possibility that the derived stationary target is other than an obstacle on the road, the radar device does not output the target data of the stationary target to the vehicle control device.

  Here, in order to determine whether or not the derived stationary target is an obstacle on the road, for example, a first transmission antenna that outputs a transmission wave upward with respect to the road surface and a downward transmission with respect to the road surface And a second transmitting antenna that outputs a wave.

  Then, the radar apparatus detects a stationary object based on a difference in the signal level of the reflected wave reflected from the object by the transmission wave output from the first transmission antenna and the second transmission antenna, the temporal transition of the signal level of the reflected wave, and the like. It was determined whether the sign was an obstacle on the road. As a technique related to the present invention, there is, for example, Patent Document 1.

JP 2011-221869 A

  However, even if the signal level of the reflected wave of the stationary target is a signal level based on the same reflection point, the distance between the stationary target and the vehicle, the angle at which the transmitted wave is reflected at the reflection point of the stationary target, etc. May vary due to differences. For this reason, the radar device may not be able to accurately determine whether a stationary target is an obstacle on the road based on the difference in the signal level of the reflected wave or the temporal transition of the signal level of the reflected wave. there were. As a result, the vehicle control device may not be able to perform proper vehicle control.

  An object of the present invention is to provide a technique for accurately determining whether a stationary target is an obstacle on the road.

  In order to solve the above-mentioned problem, the invention of claim 1 is a radar device that receives a reflected wave from an object and derives a stationary target, and is present at a position at the shortest vertical distance from the position of the vehicle. Determining means for determining whether or not another stationary target is present at a position in the vicinity of the reference target that is a stationary target; and the other stationary target existing at a position in the vicinity of the reference target. Setting means for easily distinguishing the reference target from a road obstacle when the number is equal to or less than a predetermined number;

  Further, the invention according to claim 2 is the radar apparatus according to claim 1, wherein the setting means is adjacent to the own lane when the reference target is within a range of the own lane on which the vehicle travels. When the number of the other stationary targets existing within the range of the adjacent lane is equal to or less than a predetermined number, the reference target is easily identified as a road obstacle.

  Further, the invention according to claim 3 is the radar apparatus according to claim 1, wherein the setting means is the position of the reference target when the reference target exists within the range of the own lane in which the vehicle travels. When the number of the other stationary targets present at a position that is a predetermined distance or more away from the vertical direction is equal to or less than the predetermined number, the reference target can be easily identified as a road obstacle.

  According to a fourth aspect of the present invention, in the radar apparatus according to any one of the first to third aspects, the setting means is configured such that when the number of the other stationary targets is equal to or smaller than a predetermined number, the reference target is A reliability value serving as an index for determining whether or not an obstacle is on the road is increased by a predetermined value.

  The invention according to claim 5 is the radar device according to any one of claims 1 to 4, further comprising detection means for detecting a stationary target existing within a predetermined range including a plurality of lanes, wherein the determination means The determination is executed in the subsequent processes only when the stationary target number existing within the predetermined range is equal to or smaller than the predetermined number in the current process.

  The invention according to claim 6 is the radar device according to claim 5, further comprising acquisition means for acquiring the speed of the vehicle including the own apparatus, wherein the detection means is when the speed of the vehicle is equal to or greater than a predetermined value. In addition, the width of the predetermined range is increased.

  The invention according to claim 7 is a radar device that receives a reflected wave from an object, derives a stationary target, and outputs target data relating to the stationary target to a data use device that uses the data. Determining means for determining whether or not another stationary target exists at a position in the vicinity of a reference target that is a stationary target existing at a position at a shortest distance in the vertical direction from the position of the vehicle; Relaxing means for relaxing the output condition of the target data related to the reference target to the data using device when the number of the other stationary targets existing in the vicinity of the reference target is equal to or less than a predetermined number And comprising.

  The invention according to claim 8 includes the radar device according to claim 7 and the data use device according to claim 7.

  The invention of claim 9 is a signal processing method of a radar apparatus for receiving a reflected wave from an object and deriving a stationary target, wherein the stationary object exists at a position at the shortest vertical distance from the position of the vehicle. Determining whether there is another stationary target at a position in the vicinity of the reference target that is the target; and the number of the other stationary targets existing at a position in the vicinity of the reference target. And a step of making it easy to distinguish the reference target from an obstacle on the road when the number is a predetermined number or less.

  According to the present invention, the radar apparatus can make it easy to distinguish a reference target as an obstacle on the road when the number of other stationary targets existing near the reference target is equal to or less than a predetermined number. It is possible to accurately determine whether is an obstacle on the road.

  Further, according to the present invention, the radar device determines that the reference target is an obstacle on the road when the number of other stationary targets existing in the adjacent lane adjacent to the own lane is equal to or less than a predetermined number. By making it easy, it can be accurately determined whether or not another target belonging to the same object as the reference target exists within the range of the adjacent lane.

  Further, according to the present invention, the radar apparatus can identify the reference target as an obstacle on the road when the number of other stationary targets in the adjacent lane is equal to or less than a predetermined number, so that it is the same as the reference target. It is possible to accurately determine whether or not another target belonging to the object exists within the range of the own lane.

  Further, according to the present invention, the radar apparatus can reliably determine that the reference target is an obstacle on the road by increasing the reliability value by a predetermined value.

  In addition, according to the present invention, the radar apparatus performs the determination in the subsequent processing only when the stationary target number existing within the predetermined range in the current processing is equal to or less than the predetermined number. When there is relatively little stationary target data that causes erroneous determination, it is possible to perform road obstacle determination processing and perform accurate determination.

  Further, according to the present invention, when the speed of the vehicle is greater than or equal to a predetermined value, the radar device increases the width of the predetermined range, thereby converting stationary target data that is not a road obstacle to data relating to the road obstacle. Can be reduced, and control that impedes the safety of the user of the vehicle, such as sudden braking, can be prevented.

  Further, according to the present invention, the radar device can detect target data related to the reference target to the data using device when the number of other stationary targets existing near the reference target is equal to or less than a predetermined number. By relaxing the output conditions, target data required for vehicle control can be reliably output to the vehicle control device.

  In addition, according to the present invention, the vehicle control device can reliably acquire target data that requires vehicle control from the radar device, and can perform vehicle control that ensures the safety of the user of the vehicle.

FIG. 1 is a diagram illustrating a configuration of a vehicle control system according to the first embodiment. FIG. 2 is a diagram illustrating a configuration of the radar apparatus. FIG. 3 is a diagram showing the configuration of the antenna. FIG. 4 is a diagram for explaining the transmission range of the transmission wave. FIG. 5 is a diagram illustrating the relationship between the transmitted wave and the reflected wave. FIG. 6 is a diagram illustrating an example of a frequency spectrum. FIG. 7 is a diagram illustrating an example of an angle spectrum. FIG. 8 is a process flowchart of the data acquisition process. FIG. 9 is a processing flowchart for determining an obstacle on the road. FIG. 10 is a processing flowchart for determining an obstacle on the road. FIG. 11 is a diagram illustrating an example in which the determination unit selects reference target data. FIG. 12 is a diagram illustrating an example of positions in the vicinity of the reference target data. FIG. 13 is a diagram illustrating another example of positions in the vicinity of the reference target data. FIG. 14 is a process flowchart for determining whether filter data can be output. FIG. 15 is a diagram illustrating a configuration of a radar apparatus according to the second embodiment. FIG. 16 is a process flowchart illustrating a data acquisition process according to the second embodiment. FIG. 17 is a processing flowchart showing processing for determining the surrounding environment. FIG. 18 is a process flowchart for determining an obstacle on the road. FIG. 19 is a process flowchart for determining an obstacle on the road. FIG. 20 is a diagram illustrating a configuration of a radar apparatus according to the third embodiment. FIG. 21 is a diagram for explaining the change of the predetermined range according to the host vehicle speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
<1. System block diagram>
FIG. 1 is a diagram illustrating a configuration of a vehicle control system 10 according to the first embodiment. The vehicle control system 10 is provided in a vehicle such as an automobile. Hereinafter, a vehicle provided with the vehicle control system 10 is referred to as “own vehicle”. The traveling direction of the host vehicle is referred to as “front”, and the direction opposite to the traveling direction is referred to as “rear”. As shown in the figure, the vehicle control system 10 includes a radar device 1 and a vehicle control device 2.

  The radar apparatus 1 according to the present embodiment uses FM-CW (Frequency Modulated Continuous Wave) which is a frequency-modulated continuous wave to detect a target including a moving target and a stationary target existing around the host vehicle. To derive. A moving target is a target that moves at a certain speed and has a relative speed different from the speed of the host vehicle. The stationary target is a target having a relative speed that is substantially the same as the speed of the host vehicle.

  The radar apparatus 1 also has a distance (hereinafter referred to as “longitudinal distance”) (m) until a reflected wave reflected from the object is received by the receiving antenna of the radar apparatus 1, and a relative speed of the object with respect to the host vehicle (km / h) Deriving target data having target information that is a parameter such as a distance (hereinafter referred to as “lateral distance”) (m) of an object in the left-right direction (vehicle width direction) of the host vehicle. Is output to the vehicle control device 2. The lateral distance is expressed by a positive value on the right side of the host vehicle and a negative value on the left side of the host vehicle with the center position of the host vehicle being 0 (zero).

  The vehicle control device 2 is connected to a brake and a throttle of the host vehicle, and acquires target data output from the radar device 1 to control the behavior of the host vehicle. Therefore, it can be said that the vehicle control device 2 is a data use device that uses target data. For example, the vehicle control device 2 uses the target data acquired from the radar device 1 and decelerates the vehicle to avoid a collision between the own vehicle and an obstacle on the road existing in the traveling direction of the own vehicle. Protect passengers. Thereby, the vehicle control system 10 of this Embodiment functions as PCS (Pre-Crash Safety System).

<2. Radar block diagram>
FIG. 2 is a diagram illustrating a configuration of the radar apparatus 1. The radar device 1 is provided, for example, in a front grill of a vehicle, outputs a transmission wave to the outside of the vehicle, and receives a reflected wave from a target. The radar apparatus 1 mainly includes a transmission unit 4, a reception unit 5, and a signal processing device 6.

  The transmission unit 4 includes a signal generation unit 41, an oscillator 42, and a switch 43. The signal generation unit 41 generates a modulation triangular wave signal and supplies it to the oscillator 42. The oscillator 42 is a voltage controlled oscillator that controls the oscillation frequency with a voltage. The oscillator 42 converts the modulation triangular wave signal into a millimeter-wave band (for example, 76.5 GHz) signal and outputs the signal to the transmission antenna 40.

  The switch 43 connects any one of the transmission antennas 40 a to 40 d and the oscillator 42. The switch 43 is switched at a predetermined timing (for example, every 5 msec) under the control of a transmission control unit 61 described later. As a result, the transmission antenna 40 that outputs a transmission wave is switched by the switch 43.

  The transmission antenna 40 is an antenna that outputs a transmission wave TW to the outside of the host vehicle based on the transmission signal. The transmission antenna 40 is composed of four transmission antennas 40a to 40d. The transmission antennas 40a to 40d output transmission waves TW1 to TW4 and are switched at a predetermined cycle by switching of the switch 43. As described above, the transmission wave TW is output from any one of the four transmission antennas, and sequentially output by switching by the switch 43.

  The receiving unit 5 includes a plurality of receiving antennas 51 forming an array antenna, and a plurality of individual receiving units 52 connected to the plurality of receiving antennas 51. In the present embodiment, the receiving unit 5 includes, for example, four receiving antennas 51 and four individual receiving units 52. The four individual reception units 52 correspond to the four reception antennas 51, respectively. Each receiving antenna 51 receives the reflected wave RW from the target, and each individual receiving unit 52 processes the received signal obtained by the corresponding receiving antenna 51.

  Each individual receiving unit 52 includes a mixer 53 and an A / D converter 54. A reception signal obtained from the reflected wave RW received by the reception antenna 51 is amplified by a low noise amplifier (not shown) and then sent to the mixer 53. A transmission signal from the oscillator 42 of the transmission unit 4 is input to the mixer 53, and the transmission signal and the reception signal are mixed in the mixer 53. Thereby, a beat signal indicating a beat frequency which is a difference between the frequency of the transmission signal and the frequency of the reception signal is generated. The beat signal generated by the mixer 53 is converted to a digital signal by the A / D converter 54 and then output to the signal processing device 6.

  The signal processing device 6 includes a microcomputer including a CPU and a memory 63. The signal processing device 6 stores various data to be calculated, target data derived by the data processing unit 7 and the like in a memory 63 that is a storage device. The memory 63 is, for example, a RAM. The signal processing device 6 includes a transmission control unit 61, a Fourier transform unit 62, and a data processing unit 7 as functions realized by a microcomputer as software. The transmission control unit 61 controls the signal generation unit 41 of the transmission unit 4 and controls switching of the switch 43.

  The Fourier transform unit 62 performs fast Fourier transform (FFT) on the beat signal output from each of the plurality of individual reception units 52. As a result, the Fourier transform unit 62 converts the beat signals related to the reception signals of the plurality of reception antennas 51 into a frequency spectrum that is data in the frequency domain. The frequency spectrum obtained by the Fourier transform unit 62 is output to the data processing unit 7.

  The data processing unit 7 derives target data based on the frequency spectrum of each of the plurality of receiving antennas 51. The data processing unit 7 outputs the derived target data to the vehicle control device 2.

  The data processing unit 7 includes a target detection unit 71, a target processing unit 72, and a target output unit 73 as main functions. The target detection unit 71 detects target data based on the frequency spectrum obtained by the Fourier transform unit 62. The target processing unit 72 performs various processes such as a continuity determination process described later on the detected target data, a filter process, and a road obstacle determination process. The target processing unit 72 includes a determination unit 701 and a setting unit 702.

  The determination unit 701 determines whether or not there is a stationary target in the position of the shortest distance in the vertical direction in the own lane among the target data detected by the target detection unit 71. In addition, the determination unit 701 has a stationary target other than the reference target at a position in the vicinity of a stationary target (hereinafter referred to as “reference target”) that is present at the shortest vertical distance in the own lane. Determine if it exists.

  The setting unit 702 makes it easy to determine the reference target as an obstacle on the road when the number of other stationary targets existing near the reference target is equal to or less than a predetermined number. Detailed processing contents of the determination unit 701 and the setting unit 702 will be described later.

  The target output unit 73 outputs the target data processed by the target processing unit 72 to the vehicle control device 2.

<3. Antenna configuration>
Next, the configuration of the antenna 100 provided with the transmitting antenna 40 and the receiving antenna 51 of the radar apparatus 1 will be described. FIG. 3 is a diagram illustrating a configuration of the antenna 100. In FIG. 3, when the radar apparatus 1 is attached to the host vehicle, the vertical direction with respect to the road surface (the vehicle height direction of the host vehicle) is the z-axis direction, and the left-right direction (vehicle width direction of the host vehicle) is the x-axis. It is assumed that the front-rear direction (the traveling direction of the host vehicle) is the y-axis direction with respect to the road surface. In the present embodiment, the + z direction is the upward direction with respect to the road surface, the + x direction is the left direction with respect to the road surface, and the + y direction is the backward direction with respect to the road surface. The -z direction is the downward direction with respect to the road surface, the -x direction is the right direction with respect to the road surface, and the -y direction is the forward direction with respect to the road surface.

  The antenna 100 has a transmitting antenna 40 and a receiving antenna 51 on the substrate surface of the dielectric substrate 100a.

  The transmission antenna 40 includes four transmission antennas 40a to 40d. The transmission antennas 40a to 40d are arranged such that the longitudinal direction thereof is the vertical direction (z-axis direction). The transmission antennas 40a to 40d have a configuration in which two sets of transmission antennas arranged in parallel in the left-right direction (x-axis direction) are provided in two stages in the vertical direction (z-axis direction). That is, each of the transmission antennas 40a to 40d has a configuration in which each of the transmission antennas 40a to 40d is arranged in two rows and two columns with the vertical direction as the longitudinal direction.

  The transmission antennas 40a to 40d have two transmission lines TL connected to the power supply port SE, and each transmission line TL is provided with a plurality of antenna elements LF. The transmission line TL transmits a transmission signal transmitted from the power feeding port SE to the antenna element LF. Then, the output direction of the transmission wave based on the transmission signal is set according to the distance between one antenna element LF and another antenna element LF provided on one transmission line.

  The receiving antenna 51 has four receiving antennas 51. Each receiving antenna 51 is arranged in parallel in the left-right direction (x-axis direction) so that the longitudinal direction thereof is the vertical direction (z-axis direction). The receiving antenna 51 also has two transmission lines TL connected to the power supply port SE, and each transmission line TL is provided with a plurality of antenna elements LF. The antenna element of the reception antenna 51 receives the reflected wave and transmits a reception signal to the power feeding port SE via the transmission line TL.

<4. Transmission range>
Next, the transmission range of transmission waves output from the transmission antennas 40a to 40d will be described. FIG. 4 is a diagram for explaining the transmission range of the transmission wave. First, the transmission range of the transmission wave viewed from the front in the traveling direction of the host vehicle will be described.

  FIG. 4A is a diagram of the transmitting antenna 40 as seen from the front direction (−y direction) with respect to the road surface. Transmission waves TW1 to TW4 having a predetermined transmission range are sequentially output from the transmission antennas 40a to 40d. The transmission ranges of these transmission waves TW1 to TW4 are the same as the transmission ranges of transmission waves output from adjacent transmission antennas. The parts overlap.

  Next, the transmission range of the transmission waves TW1 to TW4 viewed from the side surface of the host vehicle CR will be described. FIG. 4B is a diagram when the transmission waves TW1 to TW4 are viewed from the left direction (−x direction) with respect to the road surface RT. As shown in FIG. 4B, the transmission waves TW1 and TW2 are output upward (+ z direction) with respect to the road surface RT, and the transmission waves TW3 and TW4 are output downward (−z direction) with respect to the road surface RT. Is done. Specifically, the transmission waves TW1 and TW2 are output in the direction indicated by the arrow AR1, that is, obliquely upward with respect to the road surface RT.

  Assuming that a vertical angle with respect to the road surface RT of a virtual straight line CL (hereinafter referred to as “horizontal axis CL”) extending forward and horizontally from the radar device 1 with respect to the road surface RT is ± 0 °, the angle of the arrow AR1 is The angle is θ1 ° (for example, + 5 °) in the direction perpendicular to the horizontal axis CL. Transmission waves TW3 and TW4 are output in the direction indicated by arrow AR1a, that is, obliquely downward with respect to road surface RT. The angle of the arrow AR1a is θ1a ° (eg, −5 °) in the vertical direction with respect to the horizontal axis CL.

  As described above, the transmission range of the transmission wave TW1 and the transmission range of the transmission wave TW3 are substantially symmetrical in the vertical direction with respect to the horizontal axis CL. In addition, the transmission range of the transmission wave TW2 and the transmission range of the transmission wave TW4 are also substantially symmetrical in the vertical direction with respect to the horizontal axis CL. As a result, the radar apparatus 1 including the transmission antenna 40 has different vertical heights with respect to the road surface RT of the stopped vehicle FO that is an obstacle on the road, the traffic light UO that is an upper object, and the road fence DO that is a lower object. All targets can be detected within the transmission range.

The distance at the tip of the transmission range of the transmission waves TW1 to TW4 from the position of the host vehicle CR, that is, the vertical distance L1 at which the reflected wave from the target can be received is, for example, 180 m when the position of the host vehicle CR is 0 m. Yes, the vertical angle region of each transmission range is, for example, 12 °. Next, the transmission range of the transmission waves TW1 to TW4 viewed from above the host vehicle CR will be described. FIG. 4C is a diagram when the transmission range of the transmission waves TW1 to TW4 is viewed from above (+ z direction) with respect to the road surface RT. As shown in FIG. 4C, the transmission waves TW1 and TW3 are output in the right direction (−x direction) with respect to the road surface RT, and the transmission waves TW2 and TW4 are output in the left direction (+ x direction) with respect to the road surface RT. The Specifically, the transmission waves TW1 and TW3 are output in the direction indicated by the arrow AR2, that is, in the diagonally right direction with respect to the road surface RT. The angle of the arrow AR2 is θ2 ° (for example, + 7 °) in the horizontal direction with respect to the horizontal axis CL when the horizontal angle of the horizontal axis CL with respect to the road surface RT is ± 0 °. The transmission waves TW2 and TW4 are output in the direction indicated by the arrow AR2a, that is, in the diagonally left direction. The angle of the arrow AR2a is θ2a ° (eg, −7 °) in the horizontal direction with respect to the horizontal axis CL.

  Thus, the transmission range of the transmission wave TW1 and the transmission range of the transmission wave TW2 are substantially symmetrical in the left-right direction with respect to the horizontal axis CL. Further, the transmission range of the transmission wave TW3 and the transmission range of the transmission wave TW4 are also substantially symmetrical in the left-right direction with respect to the horizontal axis CL. Thereby, the radar apparatus 1 provided with the transmission antenna 40 can detect by including all these targets in the transmission range even if the lateral distances of the stopped vehicle FO, the traffic light UO, and the road fence DO are different. . Note that the angle region in the horizontal direction of each transmission range of the transmission waves TW1 to TW4 is, for example, 25 °.

  As described above, the transmission antenna 40a outputs a transmission wave in the upper right direction with respect to the road surface RT, the transmission antenna 40b outputs a transmission wave in the upper left direction with respect to the road surface RT, and the transmission antenna 40c in the lower right direction with respect to the road surface RT. A transmission wave is output, and the transmission antenna 40d outputs a transmission wave in the lower left direction with respect to the road surface RT. The transmission wave can be output in a relatively wide range in the vertical direction and the horizontal direction. A mark can be detected.

<5. Calculation of target information>
Next, a method (principle) in which the radar apparatus 1 calculates target information including the vertical distance and relative speed of the target will be described. Here, the target information is information including a plurality of parameters of target data such as a vertical distance, a horizontal distance, and a relative speed.

  FIG. 5 is a diagram illustrating the relationship between the transmitted wave TW and the reflected wave RW. In order to simplify the explanation, the reflected wave RW shown in FIG. 5 is a reflected wave from only one ideal target. In FIG. 5, the transmission wave TW is indicated by a solid line, and the reflected wave RW is indicated by a broken line. In the upper part of FIG. 5, the vertical axis indicates frequency [GHz] and the horizontal axis indicates time [msec]. In FIG. 5, two types of transmission waves, ie, a transmission wave TW1 output in the upper right direction with respect to the road surface RT and a transmission wave TW3 output in the lower right direction with respect to the road surface RT will be described as an example. The transmission wave TW1 will be described on the assumption that the transmission wave TW1 is output in the interval from time t1 to t2, and the transmission wave TW3 is output in the interval from time t2 to t3.

  As shown in the figure, the transmission wave TW is a continuous wave whose frequency rises and falls in a predetermined cycle with a predetermined frequency as a center. The frequency of the transmission wave TW changes linearly with respect to time. Hereinafter, a section in which the frequency of the transmission wave TW increases is referred to as an “up section”, and a section in which the frequency decreases is referred to as a “down section”. The center frequency of the transmission wave TW is fo, the displacement width of the frequency of the transmission wave TW is ΔF, and the reciprocal of one cycle in which the frequency of the transmission wave TW rises and falls is fm.

  Since the reflected wave RW is a reflection of the transmission wave TW by the target, the reflected wave RW is a continuous wave whose frequency rises and falls in a predetermined cycle with a predetermined frequency as the center, similar to the transmission wave TW. However, the reflected wave RW has a time delay of time T with respect to the transmitted wave TW. This delay time T corresponds to the distance (longitudinal distance) R of the target with respect to the host vehicle, and is expressed by the following formula 1 with the speed of light (the speed of radio waves) as c.

The reflected wave RW has a frequency shift of the frequency fd with respect to the transmission wave TW due to the Doppler effect corresponding to the relative speed V of the target with respect to the host vehicle CR.

  As described above, the reflected wave RW undergoes a frequency shift corresponding to the relative velocity as well as the time delay corresponding to the longitudinal distance with respect to the transmission wave TW. For this reason, as shown in the lower part of FIG. 5, the beat frequency of the beat signal generated by the mixer 53 (the frequency of the difference between the frequency of the transmission wave TW and the frequency of the reflected wave RW) differs between the up section and the down section. Value. Hereinafter, the beat frequency in the up section is fup, and the beat frequency in the down section is fdn. In the lower part of FIG. 5, the vertical axis represents frequency [kHz] and the horizontal axis represents time [msec].

  Here, when the beat frequency when the relative velocity of the target is 0 (zero) (when there is no frequency shift due to the Doppler effect) is fr, this frequency fr is expressed by the following equation (2).

This frequency fr is a value corresponding to the delay time T described above. For this reason, the vertical distance R of the target can be obtained by the following equation 3 using the frequency fr.

Further, the frequency fd shifted by the Doppler effect is expressed by the following equation (4).

The relative velocity V of the target can be obtained by the following equation 5 using this frequency fd.

In the above description, the longitudinal distance and relative velocity of an ideal target are obtained. However, in reality, the radar apparatus 1 uses the reflected waves RW from a plurality of targets existing in front of the host vehicle CR. Receive at the same time. Therefore, the frequency spectrum obtained by the FFT processing of the beat signal obtained from the received signal by the Fourier transform unit 62 includes information on the plurality of targets.

<4. Frequency spectrum>
FIG. 6 is a diagram illustrating an example of such a frequency spectrum. The upper part of FIG. 6 shows the frequency spectrum in the up section, and the lower part of FIG. 6 shows the frequency spectrum in the down section. In the figure, the vertical axis represents signal power [dB], and the horizontal axis represents frequency [kHz].

  In the frequency spectrum of the up section shown in the upper part of FIG. 6, peaks Pu appear at the positions of three frequencies fup1, fup2, and fup3. Further, in the frequency spectrum of the down section shown in the lower part of FIG. 6, peaks Pd appear at the positions of three frequencies fdn1, fdn2, and fdn3, respectively. Hereinafter, the frequency may be referred to as another unit bin. 1 bin corresponds to about 467 Hz and corresponds to a longitudinal distance of about 0.36 m.

  If the relative velocity is not taken into consideration, the frequency at the position where the peak appears in the frequency spectrum in this way corresponds to the vertical distance of the target. For example, when attention is paid to the frequency spectrum in the up section, a target exists at each position of the vertical distance corresponding to the three frequencies fup1, fup2, and fup3 where the peak Pu appears.

  Therefore, the target detection unit 71 (see FIG. 2) extracts frequencies at which peaks Pu and Pd having power exceeding a predetermined threshold appear in the frequency spectrum of both the up section and the down section. Hereinafter, the frequency extracted in this way is referred to as “peak frequency”.

  The frequency spectrum in both the up section and the down section as shown in FIG. 6 is obtained from the received signal of one receiving antenna 51. Therefore, the Fourier transform unit 62 derives the frequency spectrum of both the up section and the down section similar to FIG. 6 from each of the reception signals of the four reception antennas 51.

  Since the four receiving antennas 51 receive the reflected wave RW from the same reflection point, the extracted peak frequencies are the same between the frequency spectra of the four receiving antennas 51. However, since the positions of the four reception antennas 51 are different from each other, the phase of the reflected wave RW is different for each reception antenna 51. For this reason, the phase information of the received signals having the same bin is different for each receiving antenna 51.

  When there are a plurality of targets at different angles of the same bin, information about the plurality of targets is included in the signal of one peak frequency. For this reason, the target detection unit 71 separates a plurality of targets existing in the same bin in the angle direction from the signal of one peak frequency by the azimuth calculation process, and estimates the angle of each target.

  Specifically, the target detection unit 71 pays attention to the reception signals of the four reception antennas 51 and estimates the angle of the target based on the phase information of these reception signals.

  Known methods for estimating the angle of such a target include ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques), MUSIC (MUltiple SIgnal Classification), and PRISM (Panchromatic Remotesensing Instrument for Stereo Mapping). A scheme can be used.

<5. Angle spectrum>
FIG. 7 is a diagram conceptually illustrating the angle estimated by the target detection unit 71 by the azimuth calculation process as an angle spectrum. In the figure, the vertical axis represents signal power [dB], and the horizontal axis represents angle [deg]. In the angle spectrum, the angle estimated by the azimuth calculation process appears as a peak Pa. Hereinafter, the angle estimated by the azimuth calculation process is referred to as “peak angle”. Thus, the plurality of peak angles simultaneously derived from the signal of one peak frequency indicate the angles and angular powers of the plurality of targets existing in the same bin.

  The target detection unit 71 performs such peak angle detection for all peak frequencies in both the up and down frequency spectrums.

  In this way, the target detection unit 71 detects the peak frequency of the target in both the up and down sections, and detects the peak angle of the target based on this peak frequency. Hereinafter, data including the peak frequency and the peak angle is referred to as peak data. The peak data includes peak information that is a plurality of parameters such as frequency, angle, and angular power.

  The target detection unit 71 associates the peak data of the up section and the peak data of the down section by pairing processing. The target detection unit 71 calculates, for example, the Mahalanobis distance MD using Equation 6 using the peak angle and the angular power of each section.

In Equation 6, θd represents an angle difference between the peak angle in the up section and the peak angle in the down section, and θp represents the power difference between the angle power in the up section and the angle power in the down section. Moreover, a and b show a coefficient.

The target detection unit 71 detects, as target data, a combination of peak data in which the Mahalanobis distance MD is a minimum value among the correlated peak data. Since the target data is obtained by associating two peak data, it is also called “pair data”. In this way, the target data includes
Pair data and filter data described later are included.

  The target processing unit 72 calculates the target information of the target data by using the peak information of the two peak data of the up section and the down section from which the pair data is based.

  The target processing unit 72 uses the peak frequency in the up section as the above-described frequency fup, and uses the peak frequency in the down section as the above-described frequency fdn. Then, the target processing unit 72 calculates the vertical distance R of the target using the above-described equations 2 and 3, and calculates the relative velocity V of the target using the above-described equations 4 and 5.

  Further, the target processing unit 72 calculates the angle θ of the target by the following formula 7, where the peak angle of the up section is θup and the peak angle of the down section is θdn. Further, the target processing unit 72 can calculate the lateral distance of the target by calculation using a trigonometric function based on the angle θ and the vertical distance R of the target.

<6. Data acquisition processing>
Next, the overall flow of the data acquisition process in which the data processing unit 7 derives the target data and outputs the target data to the vehicle control device 2 will be described. FIG. 8 is a process flowchart of the data acquisition process. The data processing unit 7 periodically repeats the data acquisition process every certain time (for example, 1/20 second). At the start of the data acquisition process, the frequency spectrum of both the up section and the down section for all four receiving antennas 51 is input from the Fourier transform unit 62 to the data processing unit 7.

  First, the target detection unit 71 of the data processing unit 7 extracts a peak frequency for the frequency spectrum (step S11). The target detection unit 71 extracts, as a peak frequency, a frequency at which a peak having a power exceeding a predetermined threshold appears in the frequency spectrum in each of the up and down sections.

  And the target detection part 71 estimates the angle and angle power of each peak data which exist in the same bin from the peak angle which concerns on the extracted peak frequency (step S12). As described above, the target detection unit 71 detects peak data in both the up and down sections.

  Next, the target detection unit 71 calculates the Mahalanobis distance MD by associating the peak data of the up section and the peak data of the down section, and performs pairing for combining the two peak data having the minimum value of the Mahalanobis distance MD. Processing is performed (step S13). As a result, the target detection unit 71 detects pair data based on the two peak data.

  The target detection unit 71 determines only the pair data relating to the actually existing object among the detected pair data as the pair data used in the subsequent processing (step S14). The detected pair data may include unnecessary data such as noise. For this reason, the target detection unit 71 determines only data relating to an actually existing object as pair data based on a predetermined condition.

  Next, the target processing unit 72 of the data processing unit 7 refers to the pair data determined in the current data acquisition processing (hereinafter referred to as “current processing”) as past data acquisition processing (hereinafter referred to as “past processing”). The continuity determination process for determining the presence / absence of association with the pair data determined in () is performed (step S15).

  The target processing unit 72 associates the pair data of the current process with the pair data of the past process having similar peak information. Then, the target processing unit 72 determines that the pair data of the current process that has been associated with each other is pair data having temporal continuity with the pair data of the past process. That is, the target processing unit 72 determines that the pair data of the current process and the pair data of the past process are pair data belonging to the same reflection point.

  In this way, the target processing unit 72 performs a determination process as to whether or not pair data having temporal continuity with respect to the pair data of the past process has been detected as the pair data of the current process.

  When the target processing unit 72 determines that there is no pair data having temporal continuity among a plurality of pair data of the current process for a pair data of a past process, the pair data of the past process Based on the above, “extrapolation” which is processing for deriving prediction data of the pair data of the current processing is performed. Target data that has been subjected to extrapolation processing in a plurality of data acquisition processes is deleted from the memory 63. The data is deleted assuming that the object related to the target data does not exist within the transmission range.

  The target processing unit 72 then associates the pair data of the past process with the pair data of the current process continuously for a predetermined number of times (for example, three times) as a result of the continuity determination process in the plurality of data acquisition processes. If it is possible, filter processing is performed (step S16). In the filter process, two pair data of the pair data detected in the previous data acquisition process (hereinafter referred to as “previous process”) and the pair data detected in the current process are smoothed in the time axis direction. It is processing.

  The target data after the filter processing is called “filter data” with respect to pair data representing instantaneous values. The pair data is the target data derived by the current processing, and the filter data is the target data obtained by adding the target data derived by the current processing and the target data detected by the past processing at a predetermined ratio. It is data.

  Next, the target processing unit 72 performs a moving object determination process, and sets a moving object flag, a closest distance target flag, and a forward vehicle flag in the filter data (step S17).

  The moving object flag indicates whether or not the object related to the filter data is moving. The nearest distance target flag indicates filter data having the smallest vertical distance among a plurality of filter data. That is, it is a flag that is turned on for a target that is present at the closest position to the host vehicle CR. The forward vehicle flag indicates whether an object related to the filter data has moved in the same direction as the host vehicle CR even once in the past.

  The moving object flag and the nearest distance target flag are set for each data acquisition process, and represent the current moving state and position of the object in real time. On the other hand, the value of the forward vehicle flag is successively inherited between temporally continuous filter data.

  The target processing unit 72 calculates the ground speed (absolute speed) of the object related to the filter data and the traveling direction based on the relative speed of the filter data and the speed of the own vehicle obtained from the vehicle speed sensor 3 of the own vehicle. To derive. The speed of the host vehicle CR is output from the vehicle speed sensor 3 to the vehicle control device 2. Therefore, the radar device 1 acquires the speed of the host vehicle CR from the vehicle control device 2. Then, the target processing unit 72 sets the moving object flag and the forward vehicle flag of the filter data based on the derived ground speed and the traveling direction.

  Next, the target processing unit 72 performs a process of determining whether or not the filter data of a stationary target that satisfies a predetermined condition among the plurality of filter data is filter data of a road obstacle (step S18). And the target process part 72 determines whether the output conditions to the vehicle control apparatus 2 are satisfy | filled with respect to several filter data including the filter data by which the process of road obstacle determination was performed (step S19). ).

  Hereinafter, in the data acquisition process, the road obstacle determination process (step S18) for determining whether or not the filter data is the filter data of the road obstacle, and whether the filter data satisfies the output condition to the vehicle control device 2 or not. The output permission determination process (step S19) for determining whether or not will be described in detail.

<6-1. Processing of road obstacle judgment>
In the process of determining an obstacle on the road, filter data (hereinafter referred to as “stationary target data”) of a stationary target that exists in the own lane and that is present at a position having the shortest vertical distance from the position of the own vehicle CR. This is a process for determining whether or not the filter data relates to a road obstacle such as a stopped vehicle. This road obstacle determination process will be described with reference to FIGS. FIG. 9 and FIG. 10 are process flowcharts for determining obstacles on the road.

  The target processing unit 72 turns off the “road obstacle possibility flag” of the filter data to be processed (step S101). The road obstacle possibility flag is a flag indicating whether or not the stationary target data has a possibility of a road obstacle. As will be described later, the stationary target data is determined to be data having a relatively high possibility of an obstacle on the road if a predetermined condition is satisfied by a plurality of data acquisition processes when this flag is on, which will be described later. “Road obstacle flag” is turned on.

  Next, the determination unit 701 of the target processing unit 72 determines whether or not there is still target data with the shortest vertical distance on the own lane among the plurality of filter data (step S102). The determination unit 701 determines whether or not reference target filter data (hereinafter referred to as “reference target data”) exists by this processing.

  Specific processing contents of this processing will be described below. The determination unit 701 determines whether or not the following conditions (a1) to (a5) are satisfied for the filter data.

(A1) Moving object flag = off (a2) Nearest distance target flag = on (a3) Longitudinal distance ≦ 120 m
(A4) Lateral distance ≥ -1.8m
(A5) Lateral distance ≦ 1.8m
Based on the conditions (a1) and (a2), it is determined that the filter data is stationary target data present at the closest position to the host vehicle CR. Based on the condition (a3), it is determined that the filter data is data existing ahead of the host vehicle CR. Based on the conditions (a4) and (a5), it is determined that the filter data is data existing in the own lane when the own vehicle CR travels substantially in the center of the own lane.

  When a certain piece of filter data satisfies all the conditions (a1) to (a5) (Yes in step S102), the determination unit 701 selects the filter data as reference target data.

  Here, a specific example in which the filter data is selected as the reference target data will be described with reference to FIG. FIG. 11 is a diagram illustrating an example in which the determination unit 701 selects reference target data. In FIG. 11, adjacent lanes (left adjacent lane L2 and right adjacent lane R2) are provided on the left and right of the own lane D1 on which the host vehicle CR travels, and the left back lane L3 and the right adjacent lane R2 are on the left side of the left adjacent lane L2. A right back lane R3 is provided on the right side. And filter data T1 exists in the area | region of the own lane area | region AS whose longitudinal distance is 120 m or less with respect to the own vehicle CR, and lateral distance +/- 1.8m (a3, a4, and a5 satisfaction). When the moving object flag of the filter data is off (a1 satisfaction) and the nearest distance target flag is on (a2 satisfaction), the determination unit 701 selects the filter data T1 as the reference target data T1.

  Returning to the process of step S102 of FIG. 9, when there is no filter data satisfying all the conditions (a1) to (a5) (No in step S102), the determination unit 701 selects the reference target data. Then, the road obstacle determination process is terminated.

  Next, the determination unit 701 determines whether other stationary target data exists at a position near the reference object data. By this process, it is determined whether or not there is still target data (hereinafter referred to as “related target data”) belonging to the same object as the object to which the reference target data belongs.

  Specific processing contents of this processing will be described below. The determination unit 701 determines whether or not the following conditions (b1) to (b6) or (b1) to (b4) and (b7) and (b8) are satisfied for the filter data.

(B1) Moving object flag = off (b2) Longitudinal distance ≦ 120 m
(B3) Vertical distance of reference target data−Vertical distance of filter data ≧ −50 m
(B4) Vertical distance of reference target data−Vertical distance of filter data ≦ 50 m
(B5) Lateral distance <-1.8m
(B6) Lateral distance ≧ −5.4 m
(B7) Lateral distance> 1.8m
(B8) Lateral distance ≤ 5.4m
Based on the conditions (b1) and (b2), it is determined that the filter data is stationary target data existing in front of the host vehicle CR. Based on the conditions (b3) to (b8), it is determined that the filter data exists within a range belonging to the same object with respect to the position of the reference target data T1. Specifically, it is determined that the filter data exists within the range of the left adjacent lane L2 based on the conditions (b5) and (b6). Further, it is determined by the conditions (b7) and (b8) that the filter data exists within the range of the right adjacent lane R2.

  Then, the determination unit 701 includes all conditions (condition A) in which the filter data is (b1) to (b6), and all conditions (condition B) of (b1) to (b4), (b7), and (b8). If neither of the conditions (Condition A) and (Condition B) is satisfied (Yes in Step S103), it is determined whether or not the filter data is related target data in the process of Step S104. Perform based on judgment conditions.

  That is, when the determination unit 701 determines in the process of step S103 that there is no filter data that may be related target data at a position near the reference target data T1 as a result of the determination based on the predetermined condition, In the process of S104, based on another condition, it is determined whether or not there is filter data that may be related target data at a position in the vicinity of the reference target data T1.

  Note that the case where the filter data satisfies either of the conditions (condition A) and (condition B) in the process of step S103 (No in step S103) will be described later.

  Here, the range in which the filter data is determined to be the related target data in the process of step S103, that is, the position in the vicinity of the reference target data will be specifically described with reference to FIG. FIG. 12 is a diagram illustrating an example of positions in the vicinity of the reference target data. In FIG. 12, the filter data to be determined is a vertical distance of 120 m or less (b2 satisfaction) with respect to the host vehicle CR, within a vertical distance of ± 50 m with respect to the reference target data T1, and a horizontal distance of -1. When it exists in the range of the left adjacent range AL of less than 8 m to −5.4 m or more (b3, b4, b5, and b6 satisfaction) and the moving object flag is off (b1 satisfaction), the determination unit 701 The filter data is determined as related target data.

  For example, when the filter data related to an upper object such as a road sign or a traffic light is reference target data, the filter data related to a member such as a steel pillar supporting the upper object may exist within the range of the adjacent lane. Therefore, when the filter data exists in any one of the left adjacent range AL and the right adjacent range AR, the determination unit 701 determines that the filter data is related target data.

  In addition, the filter data has a vertical distance of 120 m or less (b2 satisfaction) with respect to the host vehicle CR, a vertical distance of ± 50 m or less with respect to the reference target data T1, and a lateral distance of +1.8 m to +5.4 m or less. When it exists within the range of the adjacent range AR (b3, b4, b7, and b8 satisfaction) and the moving object flag is off (b1 satisfaction), the determination unit 701 determines that the filter data is related target data.

  On the other hand, when there is no filter data in any of the left adjacent range AL and the right adjacent range AR, the determination unit 701 determines that there is no filter data that may be related target data. .

  Returning to the process of step S104 in FIG. 9, the determination unit 701 determines whether there is filter data that may be related target data based on a determination condition different from the determination condition described in step S103. Determine.

  Specific processing contents of this processing will be described below. The determination unit 701 determines whether the following conditions (c1) to (c7) are satisfied for the filter data.

(C1) Moving object flag = off (c2) Longitudinal distance ≦ 120 m
(C3) Vertical distance of reference target data−Vertical distance of filter data ≧ −50 m
(C4) Vertical distance of reference target data−Vertical distance of filter data ≦ 50 m
(C5) Lateral distance ≧ −1.8 m
(C6) Lateral distance ≦ 1.8m
(C7) Vertical distance of reference target data−Vertical distance of filter data ≦ −3.0 m
The conditions (c1) to (c4) are the same as the conditions (b1) to (b4) described above. Based on the conditions (c5) and (c6), it is determined that the filter data exists in the own lane D1 when the own vehicle CR travels substantially in the center of the own lane D1. Depending on the condition of (c7), the filter data may belong to the same object as the reference target data related to the obstacle on the road, or may belong to the same object as the reference target data related to the upper object It is determined whether the data is characteristic.

  When the filter data does not satisfy all the conditions (c1) to (c7) (Yes in step S104), the determination unit 701 has filter data that may be related target data with respect to the reference target data. Otherwise, assuming that the reference target data may be filter data related to a road obstacle, the road obstacle possibility flag of the reference target data is turned on (step S105 shown in FIG. 10). Then, the determination unit 701 determines whether the vertical distance of the reference target data whose road obstacle possibility flag is on is 50 m or more (step S106).

  Note that the processing when the filter data satisfies all the conditions (c1) to (c7) in the processing of step S104 (No in step S104) will be described later.

  Here, a range in which the filter data is determined to be related target data, that is, a position in the vicinity of the reference target data will be described with reference to FIG. FIG. 13 is a diagram illustrating another example of the vicinity position of the reference target data. In FIG. 13, the filter data to be determined is a vertical distance of 120 m or less (c2 satisfaction) with respect to the host vehicle CR, a vertical distance within ± 50 m, and a horizontal distance within ± 1.8 m with respect to the reference target data T1. If the moving object flag is OFF (c1 satisfaction), the determination unit 701 determines that the filter data is related target data.

  For example, when the filter data related to an upper object such as an emergency light provided in the upper part of the tunnel is the reference target data, a plurality of such emergency lights should be provided at substantially equal intervals in the vehicle traveling direction. There is. Therefore, when filter data exists in the own lane range AP range from the position of the reference target data T1 having the shortest vertical distance with respect to the own vehicle CR, the determination unit 701 determines that the filter data is related target data. .

  On the other hand, when the filter data is within the same object range AQ within the vertical distance +3.0 m and the horizontal distance ± 1.8 m from the position of the reference target data T1, It is determined that there is no filter data that may be related target data. The filter data existing within the same object range AQ is considered to be filter data relating to another reflection point of the stopped vehicle, for example, and there is a high possibility of data belonging to the same road obstacle as the reference target data. Therefore, the determination unit 701 determines that the filter data existing in such a range does not satisfy the condition of the related target data.

  When the filter data does not exist in the own lane range AP range, the determination unit 701 determines that there is no filter data that may be related target data.

  Returning to the processing of step S106 in FIG. 10, when the vertical distance of the reference target data is 50 m or more (Yes in step S106), the determination unit 701 indicates whether the reference target data is likely to be an obstacle on the road. The value of the road obstacle probability counter is incremented by 1 (step S107). When the vertical distance of the reference target data is less than 50 m (No in step S106), the determination unit 701 holds the value of the road obstacle probability counter (± 0) (step S108).

  The reason why the counter is increased when the vertical distance of the reference target data is 50 m or more is that the reflected wave of the target is received by the radar apparatus 1 even if the obstacle on the road is a certain distance away, and the target data Is derived. In other words, when the upper object is at a certain distance, the reflected wave of the target is not received by the radar apparatus 1 and the target data may not be derived. When the vertical distance of the reference target data is less than 50 m, the reflected wave is received by the radar apparatus 1 regardless of whether it is an obstacle on the road or an upper object. As a result, it is difficult to determine whether the target data is target data of obstacles on the road or target data of upper objects. Therefore, when the vertical distance of the reference target data is less than 50 m, the determination unit 701 holds the value of the road obstacle probability counter for the reference target data.

  After setting the value of the road obstacle probability counter, the determination unit 701 determines whether or not the road obstacle flag in the reference target data is off (step S109). The road obstacle flag is a flag that is turned on with respect to the reference target data when the road obstacle probability counter of the reference target data is equal to or greater than a predetermined value. It is a flag indicating that the possibility of the target data is relatively high.

  When the road obstacle flag of the reference target data is off (Yes in step S109), the determination unit 701 determines whether the road obstacle probability counter of the reference target data is 10 or more (step S110). That is, the determination unit 701 determines whether or not the reference target data satisfies a determination condition that the possibility of an obstacle on the road is relatively high.

  In order to satisfy this determination condition, the reference target data needs to satisfy the condition that the vertical distance is 50 m or more in the data acquisition process at least 10 times and the road obstacle possibility flag is turned on. is there.

  When the road obstacle probability counter of the reference target data is 10 or more (Yes in step S110), the determination unit 701 sets the road obstacle flag of the reference target data from off to on (step S111). In addition, the determination part 701 complete | finishes a process, when the road obstacle probability counter of reference | standard target data is less than 10 (it is No at step S110).

  Returning to the process of step S109, when the road obstacle flag of the reference target data is on (No in step S109), the determination unit 701 determines whether the road obstacle probability counter of the reference target data is 0 or less. To do. When the road obstacle probability counter of the reference target data is 0 or less (Yes in step S112), the determination unit 701 sets the road obstacle flag of the reference target data from on to off (step S113). When the road obstacle flag is turned off, the reference target data becomes target data with a low possibility of a road obstacle.

  In the process of step S103 in FIG. 9, the determination unit 701 determines that the filter data exists in one of the left adjacent range AL and the right adjacent range AR, and that the filter data is related target data. In the case (No in step S103), the value of the road obstacle probability counter of the reference target data is decreased by 5 (step S114), and the process is terminated. Further, when the determination unit 701 determines in the process of step S104 that the filter data exists within the range of the own lane range AP and the filter data is related target data (No in step S104), the reference target The value of the on-road obstacle probability counter of data is decreased by 5 (step S114), and the process is terminated.

<6-2. Processing for determining whether output is possible>
Next, the determination unit 701 determines the output condition to the vehicle control device 2 for each of the filter data of the moving target (hereinafter referred to as “moving target data”) and the plurality of filter data including the stationary target data. It is determined whether it is satisfied. In this determination, the setting unit 702 of the target processing unit 72 makes it easy to distinguish the reference target data for which the road obstacle flag is on as a road obstacle. Specifically, the setting unit 702 uses the reference target data for which the road obstacle flag is turned on as target data related to the road obstacle, and relaxes the output condition so that the road control device 2 can easily output the reference target data. To do. Determining whether filter data can be output including such processing will be described with reference to FIG.

  FIG. 14 is a process flowchart for determining whether filter data can be output. In this processing flowchart, a process for determining whether to output stationary target data and moving target data is described. Regarding stationary target data, a description will be given of determination processing for filter data with a road obstacle flag on and filter data with a road obstacle flag off. Hereinafter, the determination process will be described in the order of stationary target data with the road obstacle flag turned off, stationary target data with the road obstacle flag turned on, and moving target data.

<6-2-1. Stationary target data with road obstacle flag off>
First, determination conditions for stationary target data with the road obstacle flag turned off will be described. The stationary target data with the road obstacle flag turned off is determined based on a plurality of parameters relating to the target data, whether or not it is filter data related to the road obstacle, and whether or not the output to the vehicle control device 2 is possible is determined. . Specific processing will be described below.

  The determination unit 701 determines whether the filter data to be determined is stationary target data. The determination unit 701 performs this determination based on the moving object flag of the filter data.

  When the moving object flag of the filter data is off (step S201), that is, when the filter data is stationary target data, the determination unit 701 determines whether the road obstacle flag of the filter data is on (step S202). ).

  When the road obstacle flag of the filter data is OFF (No in step S202), that is, when the filter data is not the reference target data and the data having a relatively low possibility of road obstacles, the setting unit 702 displays the filter data. A “confidence level” serving as an index indicating whether or not the data is data to be output to the vehicle control device 2 is calculated (step S203). Here, when the filter data is stationary target data, the reliability is an index indicating whether the stationary target data is data related to an obstacle on the road.

  The reliability is a value of, for example, 0 to 100, and the calculation of the reliability for the stationary target data whose road obstacle flag is off constitutes target information of the target data that is filter data and the target data. This is performed using information of a plurality of parameters including peak information of peak data.

  Specifically, the setting unit 702 sets the “vertical distance”, “vertical height”, “angle power”, “extrapolation frequency”, and “FFT power” of stationary target data whose road obstacle flag is off. The reliability is calculated from a plurality of parameters such as “average value”. Hereinafter, calculation of reliability based on these parameters will be described in order.

  The setting unit 702 sets a larger value of reliability as the vertical distance of the stationary target data is larger, and sets a smaller value of reliability as the vertical distance is smaller. In the case of an obstacle on the road, the target data is detected even at a certain distance, so if the vertical distance of the stationary target data is larger than the reference value, the stationary target may be an obstacle on the road Is expensive. Therefore, the setting unit 702 sets the reliability of the stationary target data to, for example, 60 when the vertical distance of the stationary target is small (for example, 40 m), and when the vertical distance is large (for example, 70 m). The reliability of the stationary target data is set to 70, for example.

  Thus, the reliability of stationary target data with the road obstacle flag off is set to a value of about 60% or more of the reliability depending on the vertical distance of the data, and the value increases or decreases based on parameters other than the vertical distance. To do.

  Next, the setting unit 702 increases the reliability as the vertical height of the stationary target data is lower, and decreases the reliability as the vertical height is higher. When the height of the stationary target data in the vertical direction is lower than the reference value, the stationary target data has a high possibility of an obstacle on the road existing on the road surface RT. Therefore, the setting unit 702 increases the reliability of the stationary target data by, for example, a maximum of 10 if the height of the stationary target data is low, and increases the reliability of the stationary target data if the height of the stationary target data is high. Decrease the degree by a maximum of 10 for example.

  The height in the vertical direction of the stationary target data is the transmission waves TW1 and TW2 that are output in the upper left and right directions with respect to the road surface RT, and the transmission waves TW3 and TW that are output in the lower left and right directions with respect to the road surface RT. It is calculated based on the signal level difference between the reflected waves of the upper and lower beams. For example, as the value obtained by subtracting the signal level of the reflected wave of the transmission wave TW3 from the signal level of the reflected wave of the transmission wave TW1 becomes a large value, the height value in the vertical direction is calculated as a large value.

  Next, the setting unit 702 increases the reliability as the angular power of the stationary target data is larger, and decreases the reliability as the angular power is smaller. The reflected wave from the obstacle on the road has a higher signal level than the reflected wave from the upper object. Therefore, when the angular power of the stationary target data is larger than the reference value, the stationary target data has a high possibility of an obstacle on the road. Therefore, the setting unit 702 increases the reliability of the stationary target data by, for example, a maximum of 20 if the angular power of the stationary target data is large, and increases the reliability of the stationary target data if the angular power of the stationary target data is small. Decrease the degree by, for example, a maximum of 20.

  Next, the setting unit 702 increases the reliability as the extrapolation frequency of the stationary target data is lower, and decreases the reliability as the extrapolation frequency is higher. Since the road obstacle exists on the host vehicle CR and the road surface RT, the extrapolation frequency in a plurality of data acquisition processes is lower than the upper obstacle. Therefore, when the extrapolation frequency of the stationary target data is lower than the reference value, the stationary target data has a high possibility of being an obstacle on the road. Therefore, the setting unit 702 increases the reliability of the stationary target data by, for example, a maximum of 5 if the extrapolation frequency of the stationary target data is low, and increases the reliability of the stationary target data by, for example, if the extrapolation frequency is high. Decrease up to 5.

  Next, the setting unit 702 increases the reliability as the average value of the signal level (FFT power) of the frequency spectrum in the data acquisition process in which the pair data of the stationary target data is detected is smaller than the reference value. The reliability is reduced as the average value is larger than the reference value. The average value of the FFT power is, for example, the average value of the signal level values for each bin of the frequency spectrum in one data acquisition process. When the average value of the FFT power is large, it indicates that a relatively large amount of target data exists around the stationary target data. As a result, the determination unit 701 may not be able to accurately determine whether the stationary target data is an obstacle on the road due to the influence of other target data.

  On the other hand, when the average value of the FFT power is small, it indicates that the number of targets existing around the stationary target data is relatively small. Accordingly, the determination unit 701 may be able to accurately determine whether the stationary target data is an obstacle on the road. Therefore, when the FFT power average value regarding the stationary target data is small, the setting unit 702 sets the reliability reduction value of the stationary target data to ± 0, for example. When the FFT power average value is large, the setting unit 702 The decrease value of the reliability is set to 25 at the maximum, for example.

  In this way, the setting unit 702 sets the reliability based on the vertical distance for the stationary target data whose road obstacle flag is off, and determines the reliability of the stationary target data based on a plurality of other parameters. The reliability of the stationary target data to be processed is derived by increasing / decreasing (step S203).

  Then, when the reliability of the stationary target data with the road obstacle flag turned off is 90 or more (Yes in step S204), the determination unit 701 indicates that the stationary target data is a road obstacle, and sends it to the vehicle control device 2. And the output flag to the vehicle control device 2 is turned on (step S205). When the reliability of the stationary target data with the road obstacle flag turned off is 90 or less (No in step S204), the stationary target data is not a road obstacle and is not an object to be output to the vehicle control device 2. To end the process.

<6-2-2. Stationary target data with road obstacle flag on>
Next, determination conditions for stationary target data with the road obstacle flag turned on will be described. In the processing of the stationary target data in which the road obstacle flag is off, the setting unit 702 calculates the reliability of the stationary target data based on a plurality of parameters related to the target data, and the determination unit 701 determines the reliability. Based on this, it was determined whether or not the stationary target data is an obstacle on the road, that is, whether or not it is an output target to the vehicle control device 2. On the other hand, in the processing of stationary target data whose road obstacle flag is on as described below, the setting unit 702 does not calculate the reliability based on a plurality of parameters related to the target data. Since the road obstacle flag of the stationary target data is on, the setting unit 702 assumes that the stationary target data is likely to be an obstacle on the road, and the setting unit 702 determines the reliability of the stationary target data with the road obstacle flag on. Is increased by a predetermined value (for example, reliability 80). In this way, the relatively high value reliability is set in advance for the stationary target data with the road obstacle flag on, and the reliability does not decrease based on a plurality of parameters. Therefore, the road obstacle flag is off. Compared to stationary target data, it is easier to determine an obstacle on the road.

  Then, the determination unit 701 determines whether the stationary target data whose road obstacle flag is on is actually detected or extrapolated based on the detection status of the vehicle control device 2 of the stationary target data. Determines whether or not output is possible. The stationary target data whose road obstacle flag is on is already determined to have a high possibility of a road obstacle, and a relatively high reliability is set. Since such stationary target data is highly necessary to be output to the vehicle control device 2, the determination unit 701 outputs only the detection status of the stationary target data to the vehicle control device 2 regardless of a plurality of parameters. Determine whether output is possible. As described above, the stationary target data with the road obstacle flag turned on is relaxed in terms of the output condition of the target data to the vehicle control device 2 as compared with the stationary target data with the road obstacle flag turned off. Specific processing will be described below.

  In the process of step S202 in FIG. 14, when the road obstacle flag of the stationary target data is on (Yes in step S202), the setting unit 702 sets the reliability to 80 for the stationary target data (step S202). S206). Then, the setting unit 702 sets the reliability according to the detection state of the stationary target data whose road obstacle flag is on (step S207). Specifically, the setting unit 702 sets the reliability of the stationary target data to 4 when the continuity determination process (step S15) in the data acquisition process can be associated with the target data of the past process. If it is increased and extrapolation cannot be performed, the reliability of the stationary target data is decreased by 2.

  The determination unit 701 determines whether or not the reliability of the stationary target data whose road obstacle flag is on is 90 or more (step S204). When the reliability is 90 or more (Yes in step S204), that is, when stationary target data with the road obstacle flag turned on is continuously detected in at least three data acquisition processes, the determination unit 701 determines the road obstacle. The output flag of the stationary target data with the object flag turned on is turned on (step S205). The output flag is a flag indicating whether or not the filter data is an output target to the vehicle control device 2.

  Specifically, when stationary target data with the road obstacle flag turned on is detected three times in the data acquisition process, the reliability of the stationary target data is 92 (80 + 12), and the data The output flag is turned on. If the reliability of the stationary target data with the road obstacle flag turned on is less than 90 (No in step S204), this process ends.

  As described above, when there is no related target data belonging to the same object around the reference target data existing on the own lane, the radar apparatus 1 has a relatively high possibility that the reference target data is an obstacle on the road. A reliability of a predetermined value indicating high is set. As a result, the radar apparatus 1 makes it easy to determine that the reference target data is data related to an obstacle on the road. As a result, the radar apparatus 1 can accurately determine whether or not the stationary target is an obstacle on the road. Further, the radar apparatus 1 relaxes the output condition of the reference target data to the vehicle control apparatus 2 by increasing or decreasing the reliability with respect to the reference target data for which the reliability of the predetermined value is set according to the detection situation. . Thereby, the radar apparatus 1 can output the target data required for vehicle control to the vehicle control apparatus 2 with certainty. In addition, the vehicle control device 2 can reliably acquire target data that requires vehicle control, and can perform vehicle control that ensures the safety of the user of the vehicle.

<6-2-3. Moving target data>
Next, determination conditions for moving target data will be described. As for the moving target data, the setting unit 702 sets a reliability of a predetermined value for the moving target data, as in the case of the stationary target data with the road obstacle flag on. In addition, the reliability of moving target data increases or decreases according to the detection status of the target data. When the reliability of the moving target data is 90 or more, the determination unit 701 turns on the output flag of the moving target data.

  Specifically, when the moving object flag of the filter data is on (No in step S201) in the process of step S201 in FIG. 14, the setting unit 702 sets the reliability of the moving target data to 80 (step S201). S208). Then, the setting unit 702 sets the reliability according to the detection status of the moving target data (Step S209). Specifically, the setting unit 702 sets the reliability of the moving target data to 4 when the continuity determination process (step S15) in the data acquisition process can be associated with the target data of the past process. When the number is increased and extrapolation is not possible, the reliability of the moving target data is decreased by two.

  Then, the determination unit 701 determines whether or not the reliability of the moving target data is 90 or more (step S204). If the reliability is 90 or more (Yes in step S204), that is, if the moving target is detected three times in succession in the data acquisition process, the determination unit 701 turns on the moving target data output flag ( Step S205). If the reliability of the moving target data is less than 90 (No in step S204), this process ends.

  Moving target data is more likely to collide with the host vehicle CR because the distance from the host vehicle CR changes in a short time compared to the stationary target data. The output condition to the vehicle control device 2 is relaxed rather than the stationary target data for determining Therefore, the stationary target data with the road obstacle flag on is determined based on the same output conditions as the moving target data, and is output to the vehicle control device 2 compared with the stationary target data with the road obstacle flag off. It can be said that the conditions are relaxed.

  Returning to the process of step S20 shown in FIG. 8, the target output unit 73 outputs the target data that is the filter data with the output flag on among the filter data processed by the target processing unit 72 to the vehicle control device 2. To do.

<Summary>
As described above, the determination unit 701 uses the shortest vertical distance stationary target existing within the range of the own lane D1 as the reference target, and other objects belonging to the same object as the reference target in the vicinity of the reference target. It is determined whether or not a stationary target exists. Then, the determination unit 701 has detected the reference target at a position (for example, a vertical distance of 50 m or more) at a certain distance when there is no other stationary target near the reference target in a plurality of data acquisition processes. When the reference target is relatively likely to be a road obstacle, the road obstacle flag of the reference target is turned on as a target.

  Then, the setting unit 702 increases the reliability by a predetermined value so that a reference target whose road obstacle flag is on is easily identified as a road obstacle. When the determination unit 701 detects the reference target whose reliability has been increased in this manner a plurality of times (for example, three times) continuously in time, an output flag of the reference target to the vehicle control device 2 is displayed. turn on. As a result, the radar apparatus 1 can accurately determine the stationary target of the obstacle on the road, and can reliably output the target data to the vehicle control apparatus 2. Further, the vehicle control device 2 can control the host vehicle CR so as to ensure the safety of the user based on the target data related to the obstacle on the road acquired from the radar device 1.

<Second Embodiment>
Next, a second embodiment will be described. The data processing unit 7 of the radar apparatus 1 according to the second embodiment performs a surrounding environment determination process before performing the on-road obstacle determination process of the data acquisition process described in the first embodiment. This surrounding environment determination process is a predetermined range in which past target data includes a plurality of lanes of own lane D1, left adjacent lane L2, right adjacent lane R2, left back lane L3, and right back lane R3. It is the process which determines whether it was detected in the inside.

  If the number of stationary target data detected in the predetermined range exceeds the predetermined number in the surrounding environment determination process of the past process, the data processing unit 7 does not perform the road obstacle determination process in the current process. On the other hand, if the number of stationary target data detected within a predetermined range is less than or equal to a predetermined number in the surrounding environment determination process of the past process, the data processing unit 7 performs a road obstacle determination process in the current process. . As described above, the surrounding environment determination process is performed as a preliminary process for determining whether or not the road obstacle determination process is performed.

  The configuration and processing of the radar apparatus 1 of the second embodiment are almost the same as those of the first embodiment. However, as described above, the surrounding environment determination processing is added to the data acquisition processing. Processing contents are partially different. Hereinafter, differences will be mainly described with reference to FIGS.

<7. Radar block diagram>
FIG. 15 is a diagram illustrating a configuration of the radar apparatus 1 according to the second embodiment. The data processing unit 7 of the radar apparatus 1 includes a detection unit 703.

  The detection unit 703 detects stationary target data that exists within a predetermined range including a plurality of lanes. This stationary target data is past target stationary target data. For example, it is the stationary target data of the previous process for the current process.

  When the number of stationary target data detected in the predetermined range in the previous process is equal to or less than the predetermined number, the determination unit 701 performs a road obstacle determination process in the current process.

<8. Data acquisition processing>
Next, data acquisition processing according to the second embodiment will be described. FIG. 16 is a process flowchart illustrating a data acquisition process according to the second embodiment. After the moving object determination process is performed (step S17), the detection unit 703 performs the surrounding environment determination process (step S18a).

<8-1. Processing of ambient environment judgment>
The surrounding environment determination process will be described with reference to FIG. FIG. 17 is a processing flowchart showing processing for determining the surrounding environment. The detection unit 703 detects surrounding stationary target data (step S301). Specifically, the detection unit 703 is a stationary target that exists within a predetermined range including a plurality of lanes of the own lane D1, the left adjacent lane L2, the right adjacent lane R2, the left back lane L3, and the right back lane R3. Detect data.

  Specific processing contents of this processing will be described below. The detection unit 703 detects stationary target data that satisfies all the following conditions (d1) to (d3) from among a plurality of filter data.

(D1) Longitudinal distance ≦ 120 m
(D2) Lateral distance ≧ −1.8 m
(D3) Lateral distance ≦ 1.8m
According to the conditions (condition D) of (d1), (d2), and (d3), when it is stationary target data that exists in front of the host vehicle CR and the host vehicle CR travels substantially in the center of the host lane D1, The stationary target data existing in the own lane D1 is detected.

  The detecting unit 703 detects stationary target data that satisfies all the following conditions (e1) to (e3) from among a plurality of filter data.

(E1) Longitudinal distance ≦ 120m
(E2) Lateral distance ≧ −5.4 m
(E3) Lateral distance <-1.8m
According to the conditions (condition E) of (e1), (e2), and (e3), it is stationary target data existing in front of the host vehicle CR, and when the host vehicle CR travels substantially in the center of the host lane D1, The stationary target data existing in the left adjacent lane L2 is detected.

  The detection unit 703 detects stationary target data that satisfies all the following conditions (f1) to (f3).

(F1) Longitudinal distance ≦ 120m
(F2) Lateral distance ≤ 5.4m
(F3) Lateral distance> 1.8m
According to the conditions (f1), (f2), and (f3) (condition F), it is stationary target data existing in front of the host vehicle CR, and when the host vehicle CR travels substantially in the center of the host lane D1, The stationary target data existing in the right adjacent lane R2 is detected.

  The detection unit 703 detects stationary target data that satisfies all the following conditions (g1) to (g3).

(G1) Longitudinal distance ≦ 120m
(G2) Lateral distance <-5.4m
(G3) Lateral distance ≧ −9.0 m
According to the conditions (condition G) of (g1), (g2), and (g3), when it is stationary target data that exists in front of the host vehicle CR and the host vehicle CR travels substantially in the center of the host lane D1, The stationary target data existing in the left back lane L3 is detected.

  The detection unit 703 detects stationary target data that satisfies all the following conditions (h1) to (h3).

(H1) Longitudinal distance ≦ 120m
(H2) Lateral distance> 5.4m
(H3) Lateral distance ≤ 9.0m
According to the conditions (condition H) of (h1), (h2), and (h3), when it is stationary target data that exists in front of the host vehicle CR and the host vehicle CR travels substantially in the center of the host lane D1, The stationary target data existing in the right back lane R3 is detected.

  Then, the determination unit 701 determines whether or not the peripheral target non-existence flag for the current process is off. This peripheral target non-existence flag has a predetermined number of stationary target data detected based on the above (Condition D), (Condition E), (Condition F), (Condition G), and (Condition H). This flag is turned off when the number is less than or equal to 1 (for example, 1 under each condition), and one of on and off is set for each data acquisition process instead of specific target data.

  When the surrounding target non-existence flag in the previous process is off (Yes in step S302), the determination unit 701 is detected within a predetermined range including a plurality of lanes in the surrounding target detection process in step S301 in the current process. It is determined whether or not the number of stationary target data is equal to or less than a predetermined number (first reference value) (step S303). The first reference value is, for example, a value in which the number of stationary target data for each lane is 1. When the number of stationary target data detected within the predetermined range is equal to or smaller than the first reference value (Yes in step S303), the determination unit 701 uses the peripheral target for the current process used in the subsequent peripheral environment determination process. The absence flag is turned on (step S304). Here, the case where the number is equal to or smaller than the first reference value refers to a case where the number of stationary target data of each lane is equal to or smaller than the reference value set for each lane. Specifically, the first reference value is the case where the number of stationary target data of the own lane D1, the left and right adjacent lanes L2, R2, and the left and right back lanes L3, R3 is 1, respectively. In addition, when the stationary target data detected within the predetermined range exceeds the first reference value (No in step S303), the determination unit 701 ends the process.

  Returning to the process of step S302, when the surrounding target absence flag is on (No in step S302), the determination unit 701 determines whether the number of stationary target data detected within a predetermined range is equal to or greater than the second reference value. Is determined (step S305). Here, the case where the number is equal to or greater than the second reference value refers to a case where the number of stationary target data of each lane is equal to or greater than the reference value set for each lane. Specifically, the second reference value is 3 for the number of stationary target data for the own lane D1, 2 for the number of stationary target data for the left adjacent lane L2, 2 for the number of stationary target data for the right adjacent lane R2, This is a value where the number of stationary target data of the lane L3 is 1, and the number of stationary target data of the right back lane R3 is 1.

  When the number of stationary target data detected within the predetermined range is equal to or greater than the second reference value (Yes in step S305), the determination unit 701 turns off the peripheral target non-existence flag (step S306). When the number of stationary target data detected within the predetermined range is less than the second reference value (No in step S305), the determination unit 701 ends the process.

  Next, the determination unit 701 determines whether or not the surrounding target absence flag is on in the road obstacle determination process illustrated in FIGS. 18 and 19 (step S101a in FIG. 18). Note that the determination unit 701 performs the determination in step S101a based on ON or OFF of the peripheral target absence flag set in the past process (for example, the previous process). If the peripheral target nonexistence flag in the past process is on (Yes in step S101a), the determination unit 701 turns off the road target possibility flag of the filter data derived in the current process (step S101). Processing similar to that described in the first embodiment is performed. When the surrounding target absence flag in the past process is off (No in step S101a), the determination unit 701 ends the road obstacle determination process.

  As a result, the determination unit 701 can perform road obstacle determination processing and perform accurate determination when there is relatively little stationary target data that causes a road obstacle to be erroneously determined.

<Third Embodiment>
Next, a third embodiment will be described. The data processing unit 7 of the radar apparatus 1 according to the third embodiment performs the left back lane L3 and the right back lane R3 in the peripheral target detection process (step S301 in FIG. 17) described in the second embodiment. Is changed in accordance with the speed of the host vehicle CR.

  The configuration and processing of the radar apparatus 1 of the third embodiment are substantially the same as those of the first embodiment, but the range of the left back lane L3 and the right back lane R3 as described above is the range of the host vehicle CR. By changing according to the speed, the processing contents are partially different. Hereinafter, the difference will be mainly described with reference to FIGS. 20 and 21. FIG.

<9. Radar block diagram>
FIG. 20 is a diagram illustrating a configuration of the radar apparatus 1 according to the third embodiment. The data processing unit 7 of the radar apparatus 1 includes an acquisition unit 704.

  The acquisition unit 704 acquires the speed (own vehicle speed) of the host vehicle CR from the vehicle control device 2.

<10. Change range>
Next, a specific example in which the ranges of the left back lane L3 and the right back lane R3 are changed according to the vehicle speed will be described with reference to FIG. FIG. 21 is a diagram for explaining the change of the predetermined range according to the host vehicle speed.

  The upper part of FIG. 21 shows the predetermined ranges indicated by the conditions (Condition D) to (Condition H) of the second embodiment. The speed of the host vehicle CR when the predetermined range is set is, for example, 40 km / h.

  On the other hand, when the speed of the host vehicle CR becomes 70 km / h, which is faster than 40 km / h, the range (width) of the left back lane L3 and the range (width) of the right back lane R3 are It becomes wider than at 40 km / h. That is, when the speed of the host vehicle CR is increased, the range of the left back lane L3 and the right back lane R3 is widened, and the predetermined range that is a range including a plurality of lanes is widened. When the speed of the host vehicle CR decreases, the range between the left back lane L3 and the right back lane R3 becomes narrow, and the predetermined range that includes a plurality of lanes becomes narrow. Thus, the determination unit 701 changes a predetermined range including a plurality of lanes according to the host vehicle speed of the host vehicle CR.

  Specifically, when the vehicle speed of the host vehicle CR is 70 km / h, the condition (g3) regarding the left back lane L3 is, for example, as follows.

(G3) Lateral distance ≧ −17.0 m
Moreover, the conditions of (h3) regarding the right back lane R3 are as follows, for example.

(H3) Lateral distance ≦ 17.0m
In this way, when the speed of the host vehicle CR is increased, a predetermined range including a plurality of lanes is widened so that when the speed of the host vehicle CR is relatively high, stationary target data that is not an obstacle on the road Can be reduced as data related to road obstacles, and control that impedes the safety of the vehicle user, such as sudden braking, can be prevented.

<Modification>
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. Below, such a modification is demonstrated. All the forms including the above-described embodiment and the form described below can be appropriately combined.

  In each of the above embodiments, the determination process using the conditions (b1) to (b8) regarding the determination condition of the filter data that may be related target data, and (c1) to (c7) as other conditions The determination process using conditions has been described. On the other hand, the determination unit 701 may determine filter data that may be related target data by using the following conditions (k1) to (k6) as another condition.

(K1) Moving object flag = off (k2) Longitudinal distance ≦ 120 m
(K3) Lateral distance <-5.8m
(K4) Lateral distance ≧ -15.0m
(K5) Lateral distance> 5.8m
(K6) Lateral distance ≤ 15.0m
(K7) Vertical distance of reference target data−Vertical distance of filter data ≦ −5.0 m
Based on the conditions (k1) and (k2), it is determined that the filter data is stationary target data existing in front of the host vehicle CR. Based on the conditions (k3) to (k6), it is determined that the filter data exists within a range belonging to the same object with respect to the position of the reference target data T1. Specifically, it is determined based on the conditions (k3) and (k4) that the filter data exists within a range including the left back lane L3 and a lane further left than the left back lane L3. Further, it is determined by the conditions (k5) and (k6) that the filter data exists in a range including the right back lane R3 and a lane on the right side of the right back lane R3. Depending on the condition (k7), the filter data may belong to the same object as the reference target data related to the obstacle on the road, or may belong to the same object as the reference target data related to the upper object It is determined whether the data is characteristic.

  The determination unit 701 includes all conditions (condition K) in which the filter data is (k1) to (k4) and (k7) and all conditions (k1) to (k2) and (k5) to (k7). In (Condition L), if neither of (Condition K) and (Condition L) is satisfied, there is no filter data that may be related target data with respect to the reference target data, and the reference target data Since there is a possibility of filter data relating to a road obstacle, the road obstacle possibility flag of the reference target data is turned on. When the filter data satisfies all of the conditions (condition K) and (condition L), the value of the road obstacle probability counter is decremented by 5.

  Further, in each of the above-described embodiments, it has been described that the conditions are satisfied (Yes in Step S103 and Yes in Step S104) when the related target data does not exist in the processes of Step S103 and Step S104. On the other hand, these conditions may be satisfied not only when there is no related target data in the processing of step S103 and step S104, but also when the number is less than a predetermined number (for example, 1 or less).

  Further, in each of the above embodiments, the determination unit 701 has been described as performing a road obstacle determination process on the filter data. In contrast, the determination unit 701 may perform a road obstacle determination process on the pair data. The pair data is the pair data of the current process used in the filter process and is data stored in the memory 63. The determination unit 701 may read the pair data of the current process from the memory 63 and perform a road obstacle determination process. Then, both the road obstacle determination process for the filter data and the road obstacle determination process for the pair data may be performed, or one of the processes may be performed.

  Further, in each of the above embodiments, the determination unit 701 turns on the output flag for the filter data with the reliability of 90, and the target output unit 73 outputs the filter data with the output flag on to the vehicle control device 2. Was. On the other hand, the target output unit 73 may output all the filter data to the vehicle control device 2. In this case, the filter data is provided with an index indicating whether or not the data is an obstacle on the road according to the reliability, and the vehicle control device 2 uses the target data as the target data for the vehicle control based on the index. It is determined whether or not.

  In each of the above embodiments, the left adjacent range AL is set to a lateral distance of less than −1.8 m to −5 for the detection range of filter data that may be related target data in the process of step S103 of FIG. The range corresponding to the lane width of the left adjacent lane L2 of 4 m or more was set, and the range of the right adjacent range AR was set to a range corresponding to the lane width of the right adjacent lane R2 of the lateral distance +1.8 m to +5.4 m or less. On the other hand, the range of the left adjacent range AL may include a part of the range of the left back lane L3. For example, the left adjacent range AL may have a lateral distance of less than −1.8 m to −5.8 m or more. Further, the range of the right adjacent range AR may include a part of the range of the right back lane R3. For example, the right adjacent range AR may be a range with a lateral distance of more than +1.8 m and less than +5.8 m.

  In the second embodiment, the first reference value is described as a value where the number of stationary target data in each lane is 1, and the second reference value is 3 as the number of stationary target data in the own lane D1. The number of stationary target data in the adjacent lane L2 is 2, the number of stationary target data in the right adjacent lane R2 is 2, the number of stationary target data in the left back lane L3 is 1, and the number of stationary target data in the right back lane R3 is 1. It was explained as a value. On the other hand, the first reference value may be a value other than this, for example, a value that sets the number of stationary target data of each lane to zero. The second reference value may also be a value other than this, for example, a value that sets the number of lane stationary target data to two.

  In each of the above embodiments, the description has been given assuming that the number of the transmission antennas 40 of the radar apparatus 1 is four and the number of the reception antennas 51 is four. The number of transmission antennas 40 and reception antennas 51 of the radar apparatus 1 is an example, and other numbers may be used as long as a plurality of target information can be detected.

  In each of the above embodiments, the radar apparatus 1 has been described as being provided in the front part of the vehicle (for example, in the front bumper). On the other hand, if the radar apparatus 1 is a place where a transmission wave can be output to the outside of the vehicle, the rear part (for example, rear bumper), left side part (for example, left door mirror), and right side part (for example, right door mirror) of the vehicle. You may provide in at least any one place.

  In each of the above embodiments, any output may be used from the transmission antenna as long as it can detect target information such as radio waves, ultrasonic waves, light, and lasers.

  Moreover, in each said embodiment, the radar apparatus 1 may be used other than a vehicle. For example, the radar apparatus 1 may be used for an aircraft, a ship, and the like.

  In the above embodiments, the speed of the host vehicle CR is output from the vehicle speed sensor 3 to the vehicle control device 2. Therefore, it has been described that the radar device 1 acquires the speed of the host vehicle CR from the vehicle control device 2. On the other hand, the radar apparatus 1 may acquire the speed of the host vehicle CR directly from the vehicle speed sensor 3.

  Further, in each of the above embodiments, it has been described that various functions are realized in software by the arithmetic processing of the CPU according to the program. However, some of these functions are realized by an electrical hardware circuit. Also good. Conversely, some of the functions realized by the hardware circuit may be realized by software.

DESCRIPTION OF SYMBOLS 1 Radar apparatus 2 Vehicle control apparatus 10 Vehicle control system 40 Transmission antenna 41 Signal generation part 42 Oscillator 51 Reception antenna 52 Individual reception part 53 Mixer 54 AD conversion part 61 Transmission control part 62 Fourier transform part 63 Memory

Claims (9)

  1. A radar device that receives a reflected wave from an object and derives a stationary target,
    Determining means for determining whether or not there is another stationary target at a position in the vicinity of a reference target that is a stationary target existing at a position at a shortest distance in the vertical direction from the position of the vehicle;
    Setting means for easily distinguishing the reference target as a road obstacle when the number of the other stationary targets existing in the vicinity of the reference target is equal to or less than a predetermined number;
    Providing
    A radar device characterized by the above.
  2. The radar apparatus according to claim 1, wherein
    The setting means is configured such that when the reference target is present within the range of the own lane on which the vehicle is traveling, the number of the other stationary targets existing within the adjacent lane adjacent to the own lane is predetermined. Making it easier to distinguish the reference target as an obstacle on the road when the number is less than or equal to
    A radar device characterized by the above.
  3. The radar apparatus according to claim 1, wherein
    The setting means includes the other stationary object that is present at a position that is a predetermined distance or more away from the position of the reference target in a case where the reference target exists within a range of the own lane on which the vehicle travels. Making it easier to distinguish the reference target as an obstacle on the road when the number of targets is less than or equal to a predetermined number;
    A radar device characterized by the above.
  4. The radar device according to any one of claims 1 to 3,
    The setting means, when the number of the other stationary targets is a predetermined number or less, to increase a reliability value that is an index for determining whether the reference target is an obstacle on the road;
    A radar device characterized by the above.
  5. The radar apparatus according to any one of claims 1 to 4,
    A detecting means for detecting a stationary target existing within a predetermined range including a plurality of lanes;
    The determination means performs the determination in the subsequent processing only when the stationary target existing in the predetermined range is equal to or less than the predetermined number in the current processing,
    A radar device characterized by the above.
  6. The radar apparatus according to claim 5, wherein
    It further comprises acquisition means for acquiring the speed of the vehicle including the own device,
    The detecting means widens the predetermined range when the speed of the vehicle is equal to or higher than a predetermined value;
    A radar device characterized by the above.
  7. A radar device that receives a reflected wave from an object, derives a stationary target, and outputs target data related to the stationary target to a data use device that uses the data,
    Determining means for determining whether or not there is another stationary target at a position in the vicinity of a reference target that is a stationary target existing at a position at a shortest distance in the vertical direction from the position of the vehicle;
    Relaxing means for relaxing the output condition of the target data related to the reference target to the data using device when the number of the other stationary targets existing in the vicinity of the reference target is equal to or less than a predetermined number When,
    Providing
    A radar device characterized by the above.
  8. A radar device according to claim 7;
    A data use device according to claim 7;
    Providing
    A vehicle control system.
  9. A radar apparatus signal processing method for receiving a reflected wave from an object and deriving a stationary target,
    Determining whether there is another stationary target at a position in the vicinity of a reference target that is a stationary target at a position in the shortest vertical distance from the position of the vehicle;
    When the number of the other stationary targets existing in the vicinity of the reference target is equal to or less than a predetermined number, making the reference target easy to distinguish from an obstacle on the road;
    Providing
    A signal processing method characterized by the above.
JP2014199811A 2014-09-30 2014-09-30 Rader system, vehicle control system, and signal processing method Pending JP2016070772A (en)

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US14/867,287 US10031224B2 (en) 2014-09-30 2015-09-28 Radar device, vehicle control system, and signal processing method
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